Ir(III)/MPAA-Catalyzed Mild and Selective C-H Amidation of N-Sulfonyl Ketimines: Access To Benzosultam-Fused Quinazolines/Quinazolinones.

Abstract

Ir(III)-catalyzed unprecedented mild C-H amidation for weakly coordinating cyclic N-sulfonyl ketimines, accelerated by a mono protected l-amino acid, has been developed. The method uses 1,4,2-dioxazol-5-ones as the robust amidating reagent in conjunction with a catalytic amount of silver triflate. It is highly selective and does not require a stoichiometric amount of oxidants or additives. A series of mechanistic experiments was performed to gain some insights into the reaction mechanism. The strategy provides easy access to novel benzosultam-quinazoline and benzosultam-quinazolinone hybrid scaffolds endowed with pharmaceutically relevant features.